Trolley taps



June 24, 1958 F. M. SPRINGER TROLLEY TAPS Filed June 1. 1954 R 5. Mm A VLM m5 d M a ,9 y?. @s

United States Patent O TROLLEY TAPS Fred M. Springer, Solana Beach, Calif.

Application June 1, 1954, Serial No. 433,625

8 Claims. (Cl. ZOO-115.5)

This invention relates to trolley taps and more particularly to fused trolley taps.

An object of this invention is to provide an improved means for attaching a branch circuit or conductor to a portion of an electrical energy distribution system whereby energy from said system may be supplied to electrical devices such as electric drills, locomotives, mining ma chines and the like, through means which include safety disconnect means.

Another object of this invention is to provide a device of the above character which is less expensive to manufacture, stronger, more rugged, will withstand more abuse and will therefore give better service than trolley taps known heretofore.

A further object of this invention is to provide a trolley tap of the above character having a threadless, protective insulating case which, because it does not comprise a portion of the mechanical linkage, is subjected to only minimum stress and strain forces.

A further object of this invention is to provide a trolley tap of the above character having improved air cooling of the electrical conducting members in an insulating case which is substantially explosion proof.

A further object of this invention is to provide a fuse connection for a trolley tap or the like in which a fuse member is held in compression by contact members engaging opposite ends of the fuse member.

A further object of this invention is to provide a fuse i connection of this type in which fuse contact members are mounted in yokes which embrace the fuse member and extend past each other so that when the yyokes are loaded in tension, the contact members are held against v the fuse contacts to hold the fuse member in compression.

A further object of this invention is to provide a trolley tap of the above character having a pair of links each having elongate side portions encased in insulating jackets, and a fuse contact cup secured therebetween at one end of said link and facing the other end of said link, said caps being adapted for receiving and holding a fuse between said links in axial alignment therewith. One of the links has a cable connector secured to the end thereof opposite the Contact cup and the other link is in threaded engagement with a contact hook adjacent one end thereof. The cable connector and links are housed in an insulating case having its end adjacent the cable connector open and having the contact hook extending axially through the closed end thereof and stop means on said hook adjacent said link adapted to clamp a nonconducting hand guard against the end of `said case between said stop means and the end of said link.

A further object of this invention is to provide a trolley tap having an improved cable connector having at least two angularly related slots adapted to receive and securely hold a portion of an electrical conductor.

A further object of this invention is to provide an irnproved cable connector adapted to preclude damaging of conductors secured therein.

Other objects of this invention will be apparent to those skilled in this art from the following description taken in conjunction with the accompanying drawing in which:

Figure l is a view in perspective of a preferred form of trolley tap embodying the invention;

Fig. 2 is a view in side elevation of the device illustrated in Fig. 1 partially broken away to more clearly illustrate the details of construction;

Fig. 3 is a view in cross-section taken along line III-III of Fig. 2; and

Fig. 4 is a partial view in section taken along line IV-IV in Fig. 2.

Heretofore, in construction of trolley taps, a nonconducting tubular case has been provided with a pair of end plugs having means such as threads, which mechanically engage the case to secure the plugs therein in spaced relation. Further, in such prior art trolley taps, the case and end plug form a substantially sealed vessel containing a fuse. When substantial amounts of current pass through the various members enclosed in such a case, heat is produced which causes air pressure within the closed vessel to increase. The elevateed pressure often results in mechanical failure of such prior trolley taps usually involving the non-conducting case which at times disintegrates explosively, throwing fragments which injure personnel thereby.

A trolley tap embodying the present invention is shown in the drawing. It comprises a fuse yoke assembly 5 and cable connector 6 secured within an elongated tubeshaped case 7 by contact hook 8. A portion of the fuse yoke assembly 5 and a jam nut 9 co-operate with hook 8 to clamp hand guard 10 between end 11 of case 7 and washer 12.

The fuse yoke assembly 5 comprises a pair of substantially rectangular interlinked elongated loops, yokes or links 20 and 20.

The link 20 shown may be formed by bending a piece of elongate brass, copper or other suitable electricity conducting material to form a rectangular link having sides 21 and 22 and ends 23 and 24. A reinforcing end plate 25 is secured by means such as weld or braze metal 26 to end 24 to thicken and reinforce same. A fuse contact cup 27 having walls adapted to resiliently embrace a contact cap 32 of a fuse 32 is secured as by weld or braze metal 28 to end 23 with its open mouth facing plate 25 for receiving a portion of fuse 32 and for reinforcing end 23. A threaded central aperture 31 extends through plate 25 and end 24 in coaxial alignment with contact cup 27. Sides 21 and 22 are provided with electrical insulating sheaths or jackets 29 and 30 which extend from adjacent plate 25 to adjacent cup 27.

Link 20 is substantially identical with link 2U just described. The reference characters used to denote parts of link 20, when supplemented by a prime symbol, denote corresponding parts of link 20.

As shown in Figs. 2 and 3, links 20 and 20 are assembled in coaxial alignment with fuse cups 27 and 27' facing each other. Each of the cups 27 and 27 is adapted to respectively receive and frictionally engage one of the end contact caps 32 of a fuse 32 disposed therebetween. The contact caps 32' may be readily forced into the respective cups 27 and 27 when links 20 and 20' are respectively subjected to oppositely directed forces tending to move the cups toward each other when a fuse 32 is disposed therebetween in coaxial alignment therewith. The fuse 32 under compressive axial forces holds cups 27 and 27 in positive, spaced relation and direct frictional engagement between caps 32 and cups 27 and 27 substantially precludes all but intentional separation of cups 27 and 27 from the respective caps 32.

Fuse 32 is of the usual type in which caps 32 are 3 electrically connected by a fuse link (not shown) which functions as disconnecting means in the usual manner when subjected to overload conditions.

As shown in Figs. 2 and 4, the connector 6 is firmly secured to link as by threaded stud portion 33 received in aperture 371-. A case 7 is provided for housing the assembly Comprising links 20L 20', ,fuse 32, and connector 6. Case 7 is preferably an elongated cylindrical cup having anV Aopen' end 44 and an end closed by head ll through which axial aperture .34 extends. Case 7'may be'made of any suitable electrical insulating material having sucient strength and physical impact resistance to withstand the hard use to which trolley taps are normally subiestsd; for example, laminated paper, hard rubber, cloth reinforced resin, Vor the like. rlfhe open end 44 of case 7 permits escape of gases to rapidly dissipate any 4rise in. pressure .and als@ pennits dissipation of heat when the circuit is operated'aft near Overload Condition. Case 7 is Preferably of .a size which may be comfortably grasped in the hand and of sucient length such that end 44 thereof will project beyond connector 6 to shield it from accidental contact with other conductors. A hand guard 10 lies atwise against the Vexterjor face of head 11 and Projects radially outward beyond the cylindrical exteriorface of case 7 to provide an annular .llaugelike guard for preeludins slipiiaee ef the hand of a user from thetrolley tap case into contact with the ,Contact hoek,-

Fuse yoke assembly 5 with connector 6 attached theref to, is received in case 7 with threaded aperture 3l in registry with aperture 34 and head 11. Hand guard -1t) is placed in position against the exterior face lofhead 11 with central aperture 35 extending therethrough in registry with aperture 34. Ther-ads 36 are provided adjacent the end of the shank o f contact hook S andare adaptedV f to co-operate with a jam nut 9 and the threaded aperture 31 to clamp washer 12, hand guard 10 and head 11 between nut 9 and end 24. As illustrated in Fig. 2, l prefer to place a stiff metal washer 12 between jam nut 9 and hand guard 10 to protect, stiffen and n iore firmly clamp hand guard 10 in position.

In assembling the trolley tap, I prefer to place the end portion of Contact hook 8 in threaded engagement with end 24 and reinforcing plate 2.5, as shown in Fig, `2, with the adjacent portionsof the shank of hook 8 extending successively through registering apertures 34 and 35, washer 12, and jam nut 9. Jam nut 9 may then be advanced by rotation relative to the shank of hook 8 `to effect clamping of washer 12, guard 10v and head 11 between jam nut' 9 and end 24 of link 20. As shown in Fig. l, hook 8 is suitably formed adjacent 'the free externally disposed end so as to be readily engageable with a trolley wire or other similar electrical con.- ductor. i

Connectors or binding posts used heretofore to secure branch circuiteconductors to trolley taps have been 0bjectionable because either they do not anchor the Acron-V ductor securely to the trolley, or, in anchoring the conductor securely .to the .trolley tap, tend to partially sever the conductor. The conductor is subject to repeated llexation in normal usage, which ilexation results in mechanical failure ofthe conductor at the weakened point in a relatively short period of time.

l have devised a new and novel cable conneetor 6 for securely anchoring ,a branch circuit conductor 316' to a trolley tap in such a way as to `substantially eliminate `partial severing and subsequent failure of thereonductor held therein. vCable connector 6 embodying my invention, in what presently appears to be a preferred form, is illustrated in Figs. 2 and 4. `Connector ,6 comprises a lthreaded stud portion 33 having `an integral elongate -tab or plate .37 extending axially lfrom one end thereof. Faces 38 and vv39 of plate 37'are parallel and have center lines 38 and 39' parallel to and cof.

glaner with the anis ei stud 33- A portion of plate l37 comprises an integral dovetail shaped tongue 40 disposed between a pair of converging U-shaped slots 4l and 42. Tongue 40 is of substantially isosceles trapezoidal cross section taken parallel to the plane of center lines 38' and 39.

VIn the preferred form shown, the angles A are ap proximately 60 and angles B are approximately 75. As shown, tongue 40 extends perpendicularly to the plane of center lines 38 and 39'. The parallel sides of U-slot 41 are spaced apart a distance substantially equal to the diameter of conductor 36 and are joined by the intermediate semi-cylindrical end wall disposed on the l opposite side of the plane of center lines'38 and 39.

The sides of slot .42; are related in a manner similar to those of slot 41. The uninsulated end portion of conductor 36 is received in slots 41 and 42, as illustrated in Figs. 2 and 4, and substantially encircles the root portion of tongue 4t) with its center line lying substantially in the plane of center llines 38' and 39. The conductor, if sufficiently hard or stiif, will be securely engaged by and with the connector. However, I prefer to provide a band or wrapping 43 about connector 6 and conductor 36' to hold conductor 36 snugly about connector 6. Band 43 may be friction tape, any suitable impregnated or treated, Woven or unwoven cloth having successive layers which adhere firmly together, or the like. Y

The device of the invention illustrated in the drawing and described above, is subject to structural modification without departing from the spirit or scope of the appended claims.

Having described my invention, what I claim is new and desire to secure by Letters Patentis:

l. A fused trolley tap which comprises a trolley engaging hook member, a conductor-connector member, a pra-ir of yoke members, said hook and connector each being secured to respective yoke members, a pair of contact cups, each yoke member having a contact cup .secnred thereto and facing but spaced'from the other member secured to said yoke member, said yoke members being interlinked, movable relative to each other and adapted to be held in spaced facing relation by an elongate cartridge fuse disposed between 'and co-operatively engaging 'said contact cups which move toward each other as the hook and connector move toward aligned positions of greater separation.

A2. iA trolley tap for connecting one end of a branch electrical circuit to a trolley wire, said trolley tap comprising a pair of electricity Iconducting interlink-ed yoke links ,having elongate slides joining the end portions thereof, insulation .ooyering Vat least part of the surface of each of said elongate sides, means for co-operating with a fusse betweenadjacent ,ends of said links to holdsame in spaced Irelation at` least when said links are in tension under forces applied `to the remote ends thereof, a connector for joining Aa branch circuit conductor to the riem-ete end uf the first of said links, au elongate insulating .case having lan `open end and a closed end having an a-pertme, said case being adapted to receive and house said assembly of links, a fuse, and connector with ,the

remote `end `of the second of said links adjacent the closed .end .of said case, a hand guard haying an Vaperture therethrough, said hand guard lying flatwise against the exterior face of the closed Aend of said .case with vthe aperture therein in registry with the aperture in said case end, a Contact hook havingla portion lof its shank threaded adjacent the free end thereof, a jam nut, the threaded portion of said contact hook shank extending in succession through the jam nut, hand guard, and case end into engagement with the remote end of said second link wherebyV `said handY guard and case end :may be clamped between said jam nut and the end of said link by rotation of the yjam nut relative Vto the contact hook after the Aend portion lof the ,contact hook is infirm engagement with the second link.

3. vA trolley tap according lto claim V2 characterized by the fact that said connector comprises an elongate plate member lhaving an integral dove-tail shaped tongue extending transversely of the plate and of equilateral trapezoidal cross-section between a pair of slots converging symmetrically from one side of said plate, each of said slots being adapted to receive a portion of a conductor substantially encircling the root of said tongue and of a diameter substantially equal to the width of said slots, whereby a conductor may be securely connected to said trolley tap.

4. A trolley tap according to claim 2 characterized by the fact that said connector comprises an elongate plate member having lan integral dove-tail shaped tongue extending transversely of the plate and of equilateral trape- Zoidal transverse cross-section between a pair of slots converging symmetrically from one side of said plate, each of said slots being adapted to receive a portion of a conductor substantially encircling the root of said tongue and of a diameter substantially equal to the width ot said slots, and an encircling band urging said conductor toward said tongue intermediate said slots.

5. A connector comprising a plate member having an integral dove-tail-shaped tongue portion extending transversely thereof between a pair of conductor-receiving slots, each laterally bounded by a respective pair of parallel face portions, said slots converging symmetrically from an edge of said plate to spaced ends adjacent the root of said tongue, whereby the tongue is narrower adjacent the root than the free end thereof and whereby a conductor having a diameter substantially equal to the distance a pair of slot bounding parallel face portions are spaced from each other and extending through said slots in sequence and substantially encircling the root portion of said tongue may be rmly secured to said plate. 6. A connector comprising a plate member having an integral dove-tail-shaped tongue of s'osceles-trapezoidal cross-section, said tongue portion narrowing toward its root and extending between a pair of conductor-receiving slots which converge symmetrically from an edge of said plate to spaced blind ends adjacent the root of said tongue and band means adapted to co-operatively encircle s'aid plate and a conductor extending through said slots in sequence and substantially encircling the root portion of said tongue whereby the end portion of the conductor may be firmly secured to said plate.

7. A connector comprising an elongate plate member having an integral dove-tail-shaped tongue extending transversely of said plate with its root end adjacent the center line of said plate and its free end at an edge thereof, the lateral edge faces of said tongue being symmetrically inclined at an angle of substantially 15 to a normal to a major face of said plate, said tongue being isosceles-trapezoidal in transverse cross-section, a pair of slots laterally of said tongue, each slot having a U-shaped wall, a portion of which comprises a lateral edge face of said tongue, the width of each of said slots being adapted to receive a conductor of a diameter substantially equal to the width of s-aid slot, whereby portions of a conductor encircling the root of said tongue may be received in said slots and firmly held by said connector.

8. A connector comprising an elongate plate member having an integral dove-tail-shaped tongue extending transversely of said plate with its root end adjacent the center line of said plate and its free end at an edge thereof, the lateral edge faces of said tongue being symmetri'cally inclined at an angle of substantially 15 to a normal to a major face of said plate, said tongue being isosceles-trapezoidal in transverse cross-section, a pair of slots laterally of said tongue, each slot having a U-shaped wall, a portion of which comprises a lateral edge face of said tongue, each Lof said slots being adapted to receive a conductor of a diameter substantially equal to the width of said slot, and band means co-operatively encircling said plate and a conductor extending through said slots for binding an end portion of the conductor iirmly in position encircling the root of said tongue, whereby a conductor may be securely held by said connector.

References Cited in the le of this patent UNITED STATES PATENTS 1,358,291 Cobacker u Nov. 9, 1920 2,114,736 De Right Apr. 19, 1938 2,309,971 McLarn' Feb. 2, 1943 2,475,352 Conrad July 5, 1949 FOREIGN PATENTS 197,684 Switzerland Aug. l, 1938 732,618 France June 20, 1932 

